Harnessing the immune system against cancer: current immunotherapy approaches and therapeutic targets

Mol Biol Rep. 2021 Dec;48(12):8075-8095. doi: 10.1007/s11033-021-06752-9. Epub 2021 Oct 20.


Cancer immunotherapy is a rapidly evolving concept that has been given the tag "fifth pillar" of cancer therapy while radiation therapy, chemotherapy, surgery and targeted therapy remain the other four pillars. This involves the stimulation of the immune system to control tumor growth and it specifically targets the neoplastic cells rather than the normal cells. Conventional chemotherapy has many limitations which include drug resistance, recurrence of cancer and severe adverse effects. Immunology has made major treatment breakthroughs for several cancers such as colorectal cancer, prostate cancer, breast cancer, lung cancer, liver cancer, kidney cancer, stomach cancer, acute lymphoblastic leukaemia etc. Currently, therapeutic strategies harnessing the immune system involve Checkpoint inhibitors, Chimeric antigen receptor T cells (CAR T cells), Monoclonal antibodies, Cancer vaccines, Cytokines, Radio-immunotherapy and Oncolytic virus therapy. The molecular characterization of several tumor antigens (TA) indicates that these TA can be utilized as promising candidates in cancer immunotherapy strategies. Here in this review, we highlight and summarize the different categories of emerging cancer immunotherapies along with the immunologically recognized tumor antigens involved in the tumor microenvironment.

Keywords: CAR T cells; CTLA-4; Cancer immunotherapy; Cancer vaccines; Checkpoint inhibitor; Cytokines; Monoclonal antibodies; Oncolytic viruses; PD-1; PD-L1.

Publication types

  • Review

MeSH terms

  • Antibodies, Monoclonal / pharmacology
  • Antigens, Neoplasm / immunology
  • Antigens, Neoplasm / therapeutic use
  • Antineoplastic Agents, Immunological / therapeutic use
  • Biomarkers, Tumor
  • Humans
  • Immune System / drug effects
  • Immunologic Factors / immunology
  • Immunotherapy / methods*
  • Immunotherapy / trends
  • Molecular Targeted Therapy / methods
  • Molecular Targeted Therapy / trends
  • Neoplasms / immunology*
  • Neoplasms / therapy*
  • Tumor Microenvironment / drug effects


  • Antibodies, Monoclonal
  • Antigens, Neoplasm
  • Antineoplastic Agents, Immunological
  • Biomarkers, Tumor
  • Immunologic Factors